1. Field of the Invention
The present invention relates to a method for processing display data, and more particularly, to a method for processing display data, which employs scanning lines as processing units.
2. Description of the Related Art
With wide use of various displays in daily life, users are not satisfied to transmit information only by images. There is a further need to improve the quality of the images. To improve the quality of the images, it should increase scanning frequencies of the displays. However, with increasing the scanning frequencies of the displays, data needed to be processed in a predetermined time period are increased doubly. Thus it will largely increase the amount of data memories for the images.
Generally, there should be more input ports than output ports when processing images (for example the amount of input ports is double that of the output ports, that is including four input ports and two output ports), such that a time period for receiving data is double that for sending out the data. Because of the time relation between inputting/outputting, a conventional technology employs three groups of double data rate random access memories (DDRRAM) as a storing space for display data.
Referring to FIG. 1, a sequence diagram of a conventional method for processing image data is provided. As shown in FIG. 1, the image data are continuously inputted into DDRRAM of an image buffer. Time periods are in relation to the DDRRAM and the sequence for the data in here. For example, DDR1_W1 are first image data written into a first group of DDRRAM; DDR2_W1 are first image data written into a second group of DDRRAM; and DDR3_W1 are first image data written into a third group of DDRRAM. Furthermore, DDR1_W2 are second image data written into the first group of DDRRAM; DDR2_W2 are second image data written into the second group of DDRRAM; and DDR3_W2 are second image data written into the third group of DDRRAM.
As shown in FIG. 1, in the time period DDR1_W1, a group of image data are written into the first group of DDRRAM. After the time period DDR1_W1, that is, after the first group of DDRRAM receives the group of image data, the first group of DDRRAM begins to output the image data stored therein to another buffer (called as display buffer in following) for being displayed in a display. The output performance operates in the time period DDR1_R1 as shown in FIG. 1. Similarly, in the time period DDR2_W1, another group of image data are written into the second group of DDRRAM. After the time period DDR2_W1, the second group of DDRRAM outputs the image data stored therein to the display buffer in the time period DDR2_R1 as shown in FIG. 1. In addition, in the time period DDR3_W1, other group of image data are written into the third group of DDRRAM. After the time period DDR3_W1, the third group of DDRRAM outputs the image data stored therein to the display buffer in the time period DDR3_R1.
From FIG. 1, it is obvious that three groups of DDRRAMs must be employed to successfully input and output the data in the condition that the amount of the input ports is double that of the output ports. Thus the manufacturers seek methods for decreasing the manufacturing cost in the modern society with the keen competition and the gradual increasing material cost. However, the manufacturers are limited by the above design, and cannot find an excellent reformative method.
What is needed, is providing a method for processing image data, which can solve the above problems.